The objective of the proposed research is to identify and characterize in Hepatoma Tissue Culture cells, those membrane glycoproteins, whose level can be altered by hormones, particularly by glucocorticoids and by the peptide hormones, glucagon, insulin and growth hormone. Membrane glycoproteins were identified by two-dimensional-polyacrylamide gel analysis of cells labeled with radioactive carbohydrates or amino acids. The surface localization of these proteins could be verified by cell fractionation techniques and by external labeling using either lactoperoxidase-catalyzed iodination or NaB(3H)4 reduction of galactose oxidase-treated cells. Using these techniques, we have shown that glucocorticoids alter both cell adhesiveness, carbohydrate uptake, and composition of both surface and medium glycoproteins of hepatoma cells. We will prepare monospecific antibodies against such hormone-inducible membrane glycoproteins. These antibodies together with radioisotopic and cell fractionation methods would be used to trace the intracellular pathway of biogenesis of the inducible membrane components. In combination with cell-free synthesis, the level and extent of induction will be assessed. Variant hepatoma cells have been and will be selected for differences in adhesiveness or other cell membrane functions in response to hormone treatment. The surface membrane polypeptide composition and metabolism in these cells will be examined in the hope of defining causal relationships between the presence and absence of specific plasma membrane proteins and cell behavior, such as adhesiveness or cell-cell aggregation.